Chemistry – Page 14 – David Bradley

Alchemist Checks Oxy Cholesterol Levels

copper-alchemist The Alchemist this week learns how fluorine chemistry is blooming, how to melt proteins, and how cholesterol is all about the good, the bad, and the oxy. Also this week, a technique borrowed from organic LED fabrication could lead to a new way to manufacture tiny inorganic LEDs for next generation displays, while a conductive flip has been observed with clusters of atoms close to absolute zero. Finally, the American Chemical Society announces this years previously unsung chemical heroes from across the industry.

Previously on ChemWeb, we heard rumors of silicon neurons and the coming cyborg age, he discovers that a compound that leads to ovine Cyclops has now been synthesized for cancer drug research, and how chicken poop down on the shooting range could help solve the problem of lead in the soil. Also, in the news, a new type of fuel cell for truckers that reduces their emissions during rest periods and the increasing cost in water of producing bioethanol. Finally, a major award for a generic pharmacologist.

Swine Flu and Glutathione Supplements

Could a simple dietary change that increases glutathione, or indeed supplementation with this tripeptide be all you need to boost your immune system and ward of influenza?

Evidence mounted for glutathione itself in 2000, when Emory University researchers led by Dean Jones reported that a lozenge or oral spray containing glutathione might help prevent infection with influenza. Trials in humans had not been carried out but details were reported in Free Radical Biology and Medicine and elsewhere.

If glutathione is actually effective against influenza infection, and it may well not be, then it would presumably have to be present at the infection site – mouth and nose and upper respiratory tract. No definitive clinical trials have proven efficacy one way or the other yet.

FRIEL, H., & LEDERMAN, H. (2006). A nutritional supplement formula for influenza A (H5N1) infection in humans? Medical Hypotheses, 67 (3), 578-587 DOI: 10.1016/j.mehy.2006.02.040

Hot, Tardy Alchemist

copper-alchemist Bit late with the update for The Alchemist this week, had so much else to talk about before a slot was available, there was also the matter of our family vacation, hope readers find the info current enough to be of interest.

The Alchemist recently learned that music could be the key to the smooth running of a lab-on-a-chip, while tweaking quantum dots for the light show might be possible through physical rather than chemical changes. Imprinted polymers could remove vitamin B2 from beer giving it a longer-lasting flavor, we learn, while Japanese scientists have sniffed out the chemical basis of at least one form of aromatherapy. In the analytical arena, a simple enzyme-based test has been devised for spotting melamine adulteration in milk samples. Finally, the establishment of the InChI Trust will promote the use of chemical string theory for structure searching.

My Intute Spotlight column migrated to the all-new Hot Topics section on Intute while I was on holiday, so you can access my physical words for August here:

Inorganic oil – The stock explanation for the origins of crude oil and natural gas is that these hydrocarbons are the end product of millions of years of geochemical processing of long-dead sea creatures. But, these materials might also be found much deeper in the Earth’s mantle and may have a non-organic origin hinting at a controversial mechanism for a partial replenishment of reserves.

Over and Oort on the comet’s tale – An enormous asteroid or comet smashing into the Earth 65 million years ago killed off the dinosaurs. But, according to a new study by US scientists, published in the wake of an impact event on Jupiter, cometary collisions with Earth probably didn’t cause any more than one other extinction event during life’s history.

Nano X-ray tube – Material scientists, medical physicists, and cancer biologists will all benefit from the development by US researchers of a low-cost X-ray tube packed with sharp-tipped carbon nanotubes.

How to find new drugs for malaria

German researchers have used the powerful analytical technique of X-ray diffraction to home in on an important metabolic reaction used by all pathogenic bacteria and the malaria parasite. The detailed structure of the IspH enzyme active site they revealed, which resembles a shamrock in shape, and has an Fe-S cluster at its core, could offer a promising new target for novel antibiotics that might stave off bacterial resistance.

More details on the research can be found in my XRD column on SpectroscopyNOW this week. Meanwhile, I asked team leader Michael Groll of the Technische UniversitÃ¤t MÃ¼nchen (TUM), to expand on the implications of the work.

What is the next step now that you’ve characterized the active site?

The structure allows us to perform modeling and so look for attractive ligands and putative inhibitors of the enzyme. Furthermore, we need to understand how substrates access the enzyme, docking and release. It looks like there is a major structural rearrangement, a so-called induced-fit mechanism, between the open and the closed (ligand bound) state of the IspH enzyme.

It would be interesting to get further insights into this mechanism which might allow us to get a comprehensive overview of the catalyzed specific reaction. Since the reaction of the substrate is a reduction, the FeS-cluster in the enzyme gets oxidized, we also need to understand the mechanism of enzymatic reduction of this FeS-cluster.

How might drug targets be developed for this enzyme?

Molecular modeling and high throughput screening (HTS) will be key. It would be important to get structures of various ligands including substrate and product (currently we have only modeled the substrate, which we would like to experimentally verify by the complex structure). These new compounds and structures definitely will serve as lead structures for drug development!

Surely, bacteria will simply evolve resistance to those anyway?

Yes, that can be expected. Nevertheless, it should be mentioned that most bacteria become resistant to drugs, since they create enzymes to metabolize the drug or transport it out of the bacteria — this is nothing new. For Vancomycin, it took more than 7 years to see the first resistant strains. It is definitely worth looking for IspH inhibitors as putative new antibiotics. Moreover, it is an attractive new target, because IspH exists only in bacteria, Plasmodia and some plants, and not animals, which would mean a lower risk of side-effects.

GrÃ¤wert, T., Rohdich, F., Span, I., Bacher, A., Eisenreich, W., Eppinger, J., & Groll, M. (2009). Structure of Active IspH Enzyme from Provides Mechanistic Insights into Substrate Reduction Angewandte Chemie International Edition, 48 (31), 5756-5759 DOI: 10.1002/anie.200900548

Alchemist Taking the P

copper-alchemist The current issue of my Alchemist column on ChemWeb.com is now online:

The old alchemist’s trick of attempting to use urine as a starting material for all kinds of products could offer the twenty-first century a golden opportunity, we learn this week, while electrospinning DNA nanofibers might shed white light on new technologies without requiring a naked flame. If the alchemists were searching for everlasting life, then the discovery that a compound from Easter Island is a murine elixir may not come as a surprise. There’s also a sweet surprise for lovers of corn who are not persuaded by chemophobics to go “organic.” Turns out that the application of weedkiller to sweetcorn boosts the nutritional content of the yellow kernels. The melamine petfood scandal of 2007 and the more recent poisoning of infants in China thanks to adulterated dairy products has been investigated with a novel analytical technique that provides a baseline mark for unaffected children. Finally this week, clean fuels could emerge from a multimillion-dollar investment in the US.

Stinging Heavy Metal Resistance

Head-banging science news with a spectroscopic bent from my latest posts on the SpectroscopyNOW ezines, live June 15.

A medical tale in the sting – The venom of the eusocial bee contains three novel antimicrobial compounds known as lasioglossins, which have been structurally characterised by NMR spectroscopy. The compounds offer a new avenue for developing new antibiotics that might defeat drug-resistant bacteria.

Marine surfactant soaks up heavy metal – Atomic absorption spectroscopy (AAS) and other techniques have been used to demonstrate the effectiveness of a natural surfactant molecule in removing heavy metals from solutions for potential bioremediation applications.

Topical resistance – Crystallography by UK scientists may have uncovered the mechanism by which quinolone drugs interact with DNA and bacterial topoisomerase and so point to a better understanding of how resistance to this class of drugs emerges in meningitis and pneumonia.

Exhausted grapes fit only for compost – Multivariate analysis of the physicochemical, chemical and biological parameters of winery and distillery composts could point the way to improving the use of these generally intractable waste materials.

Cannabis Cancer, Toxic Waste, Antibiotics

The latest science news with an analytical bent from yours truly, now available in the SpectroscopyNOW ezines:

Cannabis blow back – A highly sensitive new chemical test has allowed European scientists to obtain “convincing evidence” that marijuana smoke damages DNA in ways that could increase the risk of cancer.

Toxic shock – Researchers in Spain are evaluating the “ecotoxic” properties of hazardous and toxic wastes for the aquatic environment. They suggest that the ecotoxic profile of a given waste stream can be derived from a novel battery of bioassays using statistical techniques that reveal whether dangerous levels of compounds toxic to frogs and fish are present and whether or not uber-toxins* like dioxins are at unsafe levels.

Chemical directors – Chemistry often all about activation. Now, UK chemists have found a way to control and direct the activation of important molecules used to synthesise pharmaceutical and agrochemical products. Their work also provides new insights into how bond activation works.

Enzymic activity – Researchers have obtained the first three-dimensional crystal structure of an enzyme that contains iron and helps soil microbes fend off invaders and rivals. The enzyme hydroxyethylphosphonate dioxygenase (HEPD) used by the Streptomyces soil microbe could lead to new agricultural technology, chemical catalysts, and perhaps even novel antibiotics that defeat bacterial resistance to conventional drugs.

*Yes, I know the word toxin applied only to compounds naturally derived and that attaching the uber mock prefix to this word is probably also misplaced as dioxins have a much worse reputation than they deserve, but I couldn’t help myself and they are very poisonous.

Short, Sharp Alchemist

copper-alchemist Natural quasicrystals, graphene interconnects, and photo-powered nanomotors all come into view through The Alchemist’s eyeglass this week.

Also in view, is the finding that hydrogen peroxide is more than a bleach, it’s a marshal for white blood cells to flood to the body’s injury sites. Solar-powered humidity on tap might help solve pure water shortages in some arid parts of the world.

Finally, the ACS has named its Washington DC headquarters after Clifford & Kathryn Hach Building following a $33 million donation.

More…

ChemTweets and Scientwits

I was interviewed by Faith Hayden for this week’s Chemical & Engineering News on the subject of, you guessed it, science on Twitter. This link is now free to view.

Here’s a transcript of my interview:

How long have you been Tweeting?

I joined Twitter in June 2007 under the pseudonym “@sciencebase“, which is the name of my website. I made a few sporadic tweets until I discovered twitterfeeder, which automates the process of announcing one’s latest blog posts. I probably accrued about 50 followers until I saw the light last autumn. At that point I realized that tweeting isn’t a one-way process and that the key to successfully using the service is engagement with other users.

What do you primarily use your Twitter account for?

Once I’d taken the leap from simply tweeting for my own benefit and instead started to share information, blog posts, and links to other sites, that might be useful to others and to respond to their tweets with comments and retweets, twitter really started to take off for me. I went from a few dozen followers and very few people with whom I was engaging until late 2008 to a nice group of of well over 4000 people with whom I connect regularly and who also frequent my Sciencebase.com website on a basis.

Where do you think Twitter fits in with social networking?

You would, at first glance, think it’s quite limiting having to share an idea in just 140 characters, but with a little tweaking of one’s thought processes, you can get quite a lot of information across in a tweet as well as a link to a more substantial blog post, say. As a journalist, I see it as being akin to writing a beefed up headline.

How is Twitter changing science writing and science blogging?

I think Twitter, and perhaps more so FriendFeed where are the growing communities (rooms) in the life sciences and other areas, are to some extent changing the way the community itself finds out about science blogs and discusses science-related news, results, ethics and much more…

Do you think Twitter is changing the way the public consumes science news?

Twitter is still very much in its infancy, and while there seem to be a lot of people following me as sciencebase on twitter just for my news headlines, I suspect that there are far more getting their science news fix directly from websites such as Slashdot, ScienceDaily, and Eurekalert and via newsfeed aggregators too. Currently, there seems to be a surge of interest in FriendFeed, which adds several other features useful to science types on the net that are unavailable to twitter users. I suspect Twitter will either upgrade to something more like FriendFeed or the next version of FriendFeed will supercede Twitter, at least among niche users, such as scientists.

Do you find the 140-character Tweet limiting for science posts?

Like I said before, I start with the assumption that I’m really writing a beefed up headline. It’s definitely an art, especially as you are even more limited if you’re including a shortened link and want to leave space for fellow twitter users to retweet your tweet. I’m no expert, but I do try hard.

Would you encourage seasoned scientists and Ph.D. students to add Twitter to their list of bookmarked websites?

I’d encourage everyone in science to join twitter and/or FriendFeed. There is definitely a big initial hurdle to get over before these tools become useful and often novice users will abandon them before they get to that point. Build up slowly the number of people you follow, avoid scammers and spammers like the plague. For instance, as a chemistry gad student, you’re quite unlikely to have much in common with anyone calling themselves a “social media marketing guru and SEO expert”. There are lots of science types on Twitter who you will almost certainly share interests and who will be worth engaging with. Think of it as the coffee break talk between conference lectures.

For science types on twitter who want to explore twitter and science further, two resources you might find useful – bit.ly page (almost 500 members) and http://www.twibes.com/group/scientists (more than 400 members); some overlap, also lots of science journalists, educators etc, in both now.

Red Hot Spectral Alchemist

spectral-alchemist This week, The Alchemist learns of encapsulated capsules that could emulate cells, a new glassy material for preventing debilitating leaks in solid oxide fuel cells, and a computer model that might help us develop a vaccine for H1N1 type A influenza. Also, under his gaze are ionic liquids developed to dissolve wood and the cancer drug that worryingly wipes away travelers’ fingerprints. Finally, a reminder that the RSC has drawn structure database Chemspider into its web.

Over on SpectroscopyNOW, I’ve got three more news topics on cancer, Alzheimer’s disease, and mushroom poisoning:

Cancer-killing CNTs – Carbon nanotubes have allowed spectroscopists to track the movement of cancer cells through the blood and lymph systems. They also act as markers for subsequent laser therapy to kill the cells, pointing the way to an entirely novel diagnostic and treatment regime for cancer, and potentially metastasised cancer.

Early ID of AD – New software for the automated analysis of MRI brain scans could help specialists identify cases of mild cognitive impairment years before full-blown Alzheimer’s disease is apparent, according to US researchers.

Toxic fungal triangle – Chemical analysis has revealed the lethal toxic culprit in a spate of recent food poisoning incidents among Japanese people eating mushrooms including the species Russula subnigricans. The compound, essentially a ring of three carbon atoms with an acid group, cycloprop-2-ene carboxylic acid, is well known to synthetic organic chemists and offers new insights into a potentially lethal condition known as rhabdomyolysis. The researchers tell me that aside from helping us understand this curious condition the compound probably has no biological use, it failed anticancer and antibiotic tests, they told me.

Oh, the red hot allusion..? Well, at the time of writing, I’m working wirelessly in my back garden under a sun shade in sweltering English heat…it’s almost the weekend and we have high expectations of early-summer storms drowning our Saturday barbecue party…ever the pessimist, eh?